# Equation For Capacitor Leakage Current

I'm finding a bit of a problem when trying to solve this question:

Show that the leakage current for the capacitor is given by $I = \dfrac{Q}{KP}$

where $Q$ is the charge on the plates, $K$ is the dielectric constant and $P$ is the resistivity of the dielectric.

I know the concept behind the leakage current and why it happens, but I don't know how I can prove the equation.

• Too many Ks in the formula for my liking – Andy aka May 1 '14 at 14:21
• @Andyaka: One is too many? – Dave Tweed May 1 '14 at 14:27
• @DaveTweed it's been corrected now, originally the formula said K = Q/(KP) – Andy aka May 1 '14 at 14:33

• "Dielectric constant" normally refers to the relative permittivity $\epsilon_r$ of the dielectric (relative to vacuum), and is a multiplier used with $\epsilon_0$, the permittivity of free space. In this case, I think K refers to the total permittivity of the dielectric, i.e., $\epsilon_r\epsilon_0$. This means that your E and their K are the same thing. Also, note that d and L are the same thing, so they cancel out. – Dave Tweed May 1 '14 at 15:15